Very interesting 
For whom is able to understand the subject.
It’s ok for me as I know what you’re talking about, but not sure that many people on forum can really understand your technical explanation 
In simpler words (I hope), @lordmmx9, having a 64bit OS is just more efficient than a 32bit because CPU is able to do more calculation with less instruction.
For example -a very simplified example- with a 64bits CPU with one instruction, you can made 10 addition in one fast instruction, where a 32bit CPU will need 10 [slower] instructions.
If you’re running a 32bit os on a 64bit CPU, os an applications will run slower than if you have a 64bit os on the same computer.
And for what I understand, Krita is coded to be optimized with 64bit CPU instructions.
And when it’s build for a 32bit OS, there’s a “translation” of the single fast instruction to a suit of slow instructions
The translation is made automatically by the compiler:
- but it can’t be guaranteed that compilers will continue to do this job in the future
- if you have a non-official version of Krita (ie: a 32bit version provided by a third-party) and if you have a blocking bug, probably it will be more difficult to got help (like users still using Windows 7…)
- you have to wait for distro update, you can’t use new version immediately
- you have no guarantee that distro will continue to maintain a 32bit version of Krita
After, I can understand that having a new computer can be something difficult and doing an upgrade for a 32bit to 64bit without loosing application, configuration, data, can be something difficult…
Just keep in mind that maybe one day, you should have to change to a 64bit OS to be able to continue to use Krita.
Yeah.
~35years ago, when I had a computer for the first time at home, there was 8KB memory.
Just thinking about 64KB was something insane (and few years later when my father bought a 64KB extension module, hey, I can tell you that was not insane anymore !! 
)
(yes, I’m talking about Kilobytes, it’s not an error )
Grum999